In recent years wireless networks have gained popularity and have been widely deployed. With fast deployment of wireless local area networks (WLANs), the ability of WLANs to support real time services while maintaining quality of service (QoS) requirements has become an important issue. In order to support a wide range of traffic on a wireless network, the infrastructure should be capable of supporting various quality of service (QoS) requirements, including call admission. Call admission control (CAC) plays a significant role in providing the desired quality of service in wireless networks. CAC limits the number of call connections into the network in order to reduce network congestion and call dropping. CAC operates to maximize the use of available bandwidth, either in calls accepted or traffic scheduled according to channel utilization, while minimizing a blocking probability for new calls and call drop probability for connected calls. Admission of even one more call than the call capacity can bring the WLAN from stable to unstable, causing a significant degradation of the voice quality of admitted calls. CAC should therefore be in place to ensure the quality of service. Many CAC schemes use metrics such as delay, jitter, and packet loss rate. However, these metrics do not provide an optimal call admission decision. Furthermore, CAC schemes often make the implementation complex and lead to performance degradation.